Cover for leader pins



Dec. 20, 1938.

W. A. WLESMAN COVER FOR LEADER PINS Filed Nov. 8, 1937 l/NVE/VTUR W/LL/AM A W/EEMAN;

Patented Dec. 20, 1938 I 7 UNITED STATES PATENT OFFICE COVER FOR LEADER PINS William A. Wiesman, Dayton, Ohio Application November 8, 1937, Serial No. 173,439 15 Claims. (01.164-118) This invention relates to a cover for a leader A further object of the invention is to propin of a die set or the like. vide means for attaching the cover to the punch As ordinarily used in a punch press the die set holder or removing the same therefrom -by the comprises a base or, die shoe on which is mounted manipulation of the cover itselfand without thethe die, and a movable member or punch holder use of tools.

which carries the punch. The die shoe is pro- Other objects of the invention may appear as vided with guide members, commonly called the device is described in detail. leader pins, and the punch holder is provided In the accompanying drawings Fig. 1 is a front with guideways, usually in the form of bushings elevation, partly in section, of a die set equipped which project below the punch holder and emwith leader pin covers embodying my invention; 10 brace the leader pins as the punch holder moves Fig. 2 is a sectional detail View of a modified downwardly so as to guide the punch in accurate form of the cover showing the punch holder in its relation to the die. When the punch holder is elevated position; Fig. 3 is a similar view showing ,I fully retracted these bushings are spaced some the punch holder in its lowermost position; Fig.

distance above the upperends of the leader pins 4 is a sectional view taken on the line 4-4 of 15 and it is possible for the operators hand to enter Fig. 1, showing one form of attaching device; Fig. this space. between the pin and the bushing as he 5 is a detail View showing the modified form of at manipulates the work and injury sometimes ret e ed dev e; a d 6 s a sect on taken on sults. Likewise the work will sometimes enter the line 6-6 of Fig. 5.

this space, particularly when large sheets are In these drawings I have illustrated my inven- -20 being operated upon, and this interferes with the tion, including certain modifications thereof, and proper placing of the sheet on the die and somehave shown the same as applied to a die set of a times results in injury to the sheet. Further, type Commonly p y in punch D but when the punch holder is retracted the leader it will be noted that the invention may take varipins are exposed to dust and dirt and grit may ous forms and may be applied tovarious appa- 25 accumulate thereon and cause injury thereto. fetus Where similar protection s desired. Also it is possible for metal cuttings or chips to ad- As here shown the die set comprises a base or here to the bushing, due to the lubricant thereon, die shoe 10, which supports the die II, and a and to be carried upward therewith so that when Punch o der 12, which carries the P c and the punch holder moves downwardly these chips is here shown as directly connected with a ram I4. 30

will wedge between the bushing and the leader T e d e o is Provided With a plurality of uppins, and this sometimes results in very serious right leader P In a small d e set two such damage to the die set. It has been proposed p y be suiiieient, as here shown, but in heretofore to provide guards for the leader pins larger d s s there a u y f ur or more such 5 but these have not been satisfactory and have leader p The punch holder is p v ded With not gone into extensive use. This has been due guideways receive the respective ead-e p ns in part to the ineflicient character of the guards and gu the Punch in its ove ent toward the and in some cases to their heavy and expensive d e, these guideways usually ing in the form character. Further, these guards in some inof hardened steel bushings l6 mounted in and stances interfered seriously with the applying of rigidly secured to the Punch e he bores of 40 lubricant to the leader pins and the bushings, the bushings being a urat y finished to fit the which made their use objectionable. respective leader pins.

One object of the present invention is to pm- When the die holder is in its elevated or fully vide a cover or guard for a leader pin which will retracted Position, as Shown in the bushbe of very simple but highly efiicient construction ings W be spaced some d stance above the 5 and which may be produced at a low cost. pper ends of the respect v P a d n Order to A further object of the invention is to provide p v n the per t rs hand or the work from such a cover which will adequately protect the entering the space between one of these pins and leader pin and the bushing against dust and its bushing I have provided a cover for the leader against the adherence of chips thereto. pin which is carried by the punch holder and is 5 A further object of the invention is to proof such a character that it will bridge the space vide such a cover which can be quickly and easily between the bushing and the pin when the punch attached to and detached from the punch holder holder is in its fully retracted position. This cover so that it may be quicklyv moved out of the way to is preferably in the form of .a tubular device permit of the lubrication of the leader pin. which is mounted about the bushing in line with 5 the leader pin and is rigidly secured to the punch holder so that it will move therewith. In that form of the device shown in Fig. 1 this cover comprises a single tubular element H which preferably consists of a section of thin metal tubing and which is of such length that when the punch holder is fully retracted the lower end of the cover will overlap or lie close to the upper end of the leader pin. Such a device adequately prevents the entrance of anything between the upper end of the pin and the bushing and will in some measure protect the bushing against the adherence of metal chips thereto. However, it does not protect the leader pin against dust, grit and the like which may come in contact therewith and adhere thereto, due to the lubricant thereon. Therefore, I prefer that form of the device shown in Figs. 2 and 3 in which the cover comprises a plurality of telescoping sections slidably mounted one within the other and of such length that when the punch holder is fully retracted the lowermost section of the cover will be close to or in contact with the die shoe l0. As shown in Fig. 2 this telescoping cover comprises an upper section I8 which is mounted on the punch holder and a plurality of lower sections is of successively decreasing diameters, each lower section being mounted in the next higher section for free sliding movement therein, so that the cover will be extended by gravity as the punch holder moves upwardly. In practice the lowermost section has little or no movement and remains at all times in contact with or close to the die shoe. The several sections of the tubular device or cover may be formed in any suitable manner but preferably they are cut from thin metal tubing and the lower end of each upper section is bent inwardly, as shown at 20, to form a shoulder, while the upper end of each lower section is bent outwardly, as shown at 2|, to form a shoulder which cooperates with the shoulder 20 to prevent the withdrawal of the lower section through the 'lower end of the upper section. This permits of the sections to be very quickly and easilyformed at small expense and to be quickly assembled by inserting each lower section through the upper end of the next higher section. The upper section H3 is preferably of a length substantially greater than the length of the lower sections so that when the punch holder is moved to its lowermost position, as shown in Fig. 3, the several lower sections will nest one within the other in the lower portion of the upper section 3 and will lie below the bushing it so that the latter will not contact therewith.

The cover may be attached to the punch holder in any suitable manner but, as has been stated, it is highly desirable that the connection should be of such a character that the cover may be quickly applied to and removed from the punch holder so as to permit of the ready lubrication of the leader pin and bushing. When the cover is so detached from the punch holder it will move downwardly about the leader pin into engagement with the die shoe and the upper portion of the leader pin, which is provided with lubricant grooves 22, will be exposed so that lubricant may be readily applied thereto. In the case of the telescoping cover the sections will move to the positions shown in Fig. 3 but the punch holder will be in its elevated position.

As illustrated in Figs. 1 to 4 both forms of the cover are provided with the same kind of attaching device, which is of such a character that it may be moved by the rotation of the cover, either the single section I! of Fig. 1, or the upper section E8 of Fig. 2, to move the same into attaching relation with cooperating attaching members carried by the punch holder. In this particular form of the device the punch holder has mounted therein, about the bushing 56, a series of headed studs, preferably in the form of screws 23, the heads of which are spaced short distances from the lower surface of the punch holder. The upper end of the cover is provided with a series of laterally extending lugs 24, each of which is provided with an arcuate slot 25 which is open at one end and is adapted to receive the studs 21-3, the slots being of a width less than the diameter of the heads of the studs. Thus by a mere rotation of the cover, or of the upper section thereof, it can be attached to or detached from the punch holder. To prevent the accidental disconnection of the cover from the punch holder one or more of the attaching lugs 2:: is provided with a yieldable detent which is here shown as a spring finger 26 having near its ends a projection 27 so arranged that when the lugs are in proper engagement with the studs the projection 21 will engage the heads of the studs and hold the cover against rotation. When the studs are in the form of screws they may be prevented from rotating, so as to loosen them, by flattening one side of each screw head, as shown at 28, and arranging the same so close to the cylindrical wall of the cover that the screw cannot rotate. This attaching device is also adapted to serve as a templet to enable the workman, in stalling the cover to accurately locate the studs or screws 23 in the punch holder. For this purpose each lug is provided with an aperture 29 and these apertures are spaced one from the other a distance corresponding to the spacing of the slots 25. By placing the cover, or the upper section thereof, about the bushing i6 and centering the same with relation thereto the workman is enabled to insert an implement through the apertures 29 and mark the location of each screw on the punch holder, then after removing the cover he drills and taps the punch holder at the indicated locations to receive the screws. Preferably the attaching lugs 24 are formed integral with the cover by bending outwardly parts of the upper end portion of the section of tubing from which the cover is formed, those portions of the tubing between the lugs being cut away so that the lugs may lie flat against the lower surface of the punch holder.

The particular attaching device above described is very efficient and is especially desirable when the leader pin covers are to be attached after the bushing has been hardened and inserted in the punch holder, but when the covers are to be supplied with the die set itself the attaching means may take a less expensive form, as shown in Figs. and 6. As there shown the bushing Ilia is provided with a circumferential groove 30 and the cover |8a has secured thereto and extending beyond its upper end resilient detents 3|, the upper ends of which are bent upon themselves to form projections 32 which may be sprung into the groove 30 by merely pressing the cover upwardly about the bushing, and will likewise be withdrawn by a downward pull on the cover, the upper and lower surfaces of the projection 32 being inclined to cause the detents to yield under pressure. The groove 30 may be quickly and inexpensively formed in the bushing during the process of manufacture and before the bushing is hardened.

While 1 have shown and described one embodiment of my invention, together with certain modifications thereof, I Wish it to be understood that I do not desire to be limited to the details thereof as various modifications may occur to a person skilled in the art.

Having now fully described my invention, what I claim as new and desire to secure by Letters Patent is:

1. In a die set or the like comprising a base, a guide pin carried by said base and a member movable toward and from said base and provided with a guideway to receive said guide pin, a tubular device carried by said movable member in line with said guide pin and of such length that it will bridge the space between said guideway and said pin when said movable member is in its retracted position, and quickly detachable means for securing said tubular device to said movable member.

2. In a die set or the like comprising a base, a guide pin carried by said base and a member movable toward and from said base and provided with a guideway to receive said guide pin, a tubular device carried by said movable member in line with said guide pin and of such length that it will bridge the space between said guideway and said pin when said movable member is in its retracted position, and means operable by the manipulation of said tubular device for connecting the latter with and disconnecting the same from said movable member.

3. In a die set or the like comprising a base, a guide pin carried by said base and a member movable toward and from said base and provided with a guideway to receive said guide pin, a tubular device carried by said movable member in line with said guide pin and of such length that it will bridge the space between said guideway and said pin when said movable member is in its retracted position, cooperating means carried by said movable member and said tubular device respectively for detachably securing said tubular device to said movable member, one of said means comprising a resilient member.

4. In a die set or the like comprising a base, a guide pin carried by said base and a member movable toward and from said base and provided with a guideway to receive said guide pin, a tubular device carried by said movable member in line with said guide pin and of such length that it will bridge the space between said guideway and said pin when said movable member is in its retracted position, supporting members carried by said movable member, and parts carried by said tubular device and movable by the rotation of said device into and out of supporting engagement with said supporting members.

In a die set or the like comprising a base,

a tubular device carried by said movable member in line with said guide pin and of such length that it will bridge the space between said guideway and said pin when said movable member is in its retracted position, headed studs carried by said movable member, and slotted lugs carried by said tubular device and movable into and out of engagement with the respective lugs by the rotation of said tubular device.

6. In a die set or the like comprising a base, a guide pin carried by said base and a member movable toward and from said base and provided with a guideway to receive said guide pin, a tubular device carried by said movable member in line with said guide pin and of such length that it will bridge the space between said guideway and said pin when said movable member is in its retracted position, headed studs carried by said movable member, and slotted lugs carried by said tubular device and movable into and out of engagement with the respective lugs by the rotation of said tubular device, at least one of said lugs being provided with a yieldable detent to engage the corresponding stud and hold said tubular device against rotation.

7. In a die set or the like comprising a base, a guide pin carried by said base and a member movable toward and from said base and provided with a guideway to receive said guide pin, a tubular device carried by said movable member in line with said guide pin and of such length that it will bridge the space between said guideway and said pin when said movable member is in its retracted position, headed screws mounted in said movable member, slotted lugs carried by said tubular device and movable into and out of engagement with said screws, said screws having their heads flattened on one side and arranged close to said tubular device to prevent the rotation of said screws While said lugs are in engagement therewith.

8. In a die set or the like comprising a base, a guide pin carried by said base and a. member movable toward and from said base and provided with a guideway to receive said guide pin, a tubular device carried by said movable member in line with said guide pin and of such length that it will bridge the space between said guideway and said pin when said movable member is in its retracted position, headed studs carried by said movable member, and slotted lugs carried by said tubular device and movable into and out of engagement with the respective lugs by the rotation of said tubular device, said lugs having apertures spaced apart distances corresponding to the spacing of said studs to facilitate the locating of said studs on said movable member when said tubular device is to be installed.

9. In a die set or the like comprising a base, a guide pin carried by said base, a member movable toward and from said base, and a tubular element carried by and projecting beyond the surface of said movable member in line with said pin, a second tubular element mounted about the first mentioned tubular element and bridging the space between the latter and said pin, and yieldable attaching devices carried by one of said tubular elements, the other tubular element having a part to be engaged by said attaching devices.

10. In a die set or the like comprising a base, a guide pin carried by said base, a member movable toward and from said base, and a tubular element carried by and projecting beyond the surface of said movable member in line with said pin, a second tubular element mounted about the first mentioned tubular element and bridging the space between the latter and said pin, said first mentioned tubular element having a circumferential groove, and yieldable detents carried by said second tubular element and arranged to enter said groove.

11. In a die set or the like comprising a base, a guide pin carried by said base and a member movable toward and from said base and provided with a guideway toreceive said guide pin, a tubular device carried by said movable member and embracing said pin, said device including a plurality of telescoping sections slidably connected one to the other and of such length that the lowermost section will remain close to said base when said movable member is fully retracted.

12. In a die set or the like comprising a base, a leader pin carried by said base, and a member movable toward and from said base and provided with a guideway to receive said leader pin, a collapsible cover for said leader pin comprising a tubular device having parts movable lengthwise thereof into nested relation, and quick detachable means connecting one end of said device with said movable member, said device being of such a length that it will substantially bridge the space between said base and said movable member in all positions of the latter.

13. In a die set or the like comprising a base, a guide pin carried by said base and a member movable toward and from said base and provided with a guideway to receive said guide pin, a tubular cover arranged about said guide pin and comprising a plurality of sections slidably mounted one within the other, and means for connecting the outermost section with said movable member, each upper section having its lower end portion slightly tapered to form a stop and each lowerisection having its upper end portion slightly flared'to form a stop to cooperate with the stop at the lower end of the next higher section.

14. In a die set or the like comprising a base, a guide pin carried by said base, a member movable toward and from said base, and a tubular element carried by and projecting beyond the surface of'said movable member in line with said pin, a second tubular element mounted about the first mentionedtubular element and bridging the space between the latter and said pin, and an attaching device carried by said second tubular element and cooperating with the first mentioned tubular element to detachably connect said elements one to the other.

15. A cover for a leader pin of a die set or the like comprising a section of. tubing having spaced parts at the upper end thereof cut away and having the remaining parts of said upper end bent outwardly to form attaching lugs.

WILLIAM A. WIESMAN. 

